BMW is adding nearly 185,000 vehicles in the U.S. to a 2017 recall for possible engine fires. Two years ago the company recommended that the vehicles be parked outdoors until problems are fixed. The recall expansion covers a dozen 3 Series, 5 Series and Z4 models from the 2006 model year. BMW says in documents filed with the National Highway Traffic Safety Administration that moisture can get into the cars positive crankcase ventilation valve heater and cause plastic parts to degrade. That can lead to an electrical short and possible fire even when the engine isnt on. The expansion brings the total number of vehicles recalled for the problem to about 925,000.